genetic variation + manx cats Flashcards
to not fail
Adaptations
Traits/Phenotypes which allow an organism to better survive in its environment
Allele
Alternate version of a gene
Amino acids
The building blocks of proteins
Ancestor
An organism (or species) from which other organism (or species) have evolved
Antiparallel
The two strands of a DNA molecule run in opposite directions
Asexual reproduction
Requires only one parent. All offspring are genetically identical to the parent
Bases
Adenine, cytosine, guanine, thymine
Chromosome
A long strand of DNA containing a specific set of genetic information
Complementary base pairs
A-T and G-C. Ensures the genetic code is replicated correctly during DNA replication
Crossing-over
Swapping of DNA between homologous chromosomes during the meiosis process. Increases genetic variation
Deoxyribonucleic acid
A molecule that carries the genetic code
DNA sequencing
The process of finding out the exact order of bases on a length of DNA
Dominant
An allele that is always expressed when it is present. Represented using capital letters. E.g. BB, Bb
Evolution
Gradual change in the genetic code of organisms over a long period of time. May result in the formation of a new species
Fertilisation
The process where the DNA from an egg and sperm fuse together
Gametes
Sex cells containing half the chromosomes of the parent
Genome
All the DNA in a single cell of an organism
Gene
A short segment of DNA that codes for a particular protein/phenotype
Genetic code
The bases of a gene are read in sets of three and each triplet codes for an amino acid, which in turn are joined to make a protein
Gene marker
A short segment of DNA that can be used to follow inheritance of a trait (especially if it is not visible) or determine relatedness of different organisms.
Genetic variation
The total number of different alleles in a population of organisms.
Genotype
The combination of alleles for a gene. E.g. BB, Bb, bb
Genotypic ratio
The predicted ratio of inheritance of alleles from the mating of two individuals
Heterozygous
Two different alleles in a genotype. E.g. Bb
Homologous pairs of chromosomes
Two chromosomes in a cell with the same genes on them. One chromosomes is inherited from each parent.
Homozygous
Two alleles in a genotype are the same. E.g. BB or bb
Independent segregation
Homologous pairs of chromosomes line up at random and independently assort with other homologous chromosomes during the process of meiosis.
Karyotype
A picture of all the chromosomes in a cell, ordered from largest to smallest in homologous pairs.
Meiosis
A type of cell division which produces egg and sperm cells (gametes) with half the number of chromosomes of the parent cell.
Mutation
A permanent change in the DNA sequence
Offspring
The resulting individuals of reproduction.
Pedigree chart
A branching tree diagram that tracks alleles/traits being passed through a family.
Phenotype
How an observable gene is expressed as a protein/phenotype/trait.
Phenotype ratio
The predicted ratio of phenotypes of offspring of a genetic cross.
Phylogenic tree
A diagram that orders organisms in relationship to how closely related they are. Usually starts with a common ancestor on the far left.
Proteins
Polymers of amino acids that make up our traits
Punnett square
A method of showing the probability of all the potential offspring genotypes and phenotypes that can occur from mating two individuals
Population
Number of organisms of the same species living in a defined area.
Recessive
An allele that is only expressed in the phenotype when the genotype is homozygous (bb)
Sexual reproduction
Reproduction involving two parents. Offspring inherit half their DNA from each parent.
Species
A group of organisms that can breed with each other and produce fertile offspring.
Trait
A feature of an organism (phenotype)
Triplet code
Bases of genes are read in threes (triplets), each triplet codes for an amino acid to build a protein.
Monomer
Single unit that is the building block of larger molecules
Organism
A living thing
Polymer
A series of monomers joined together by chemical bonds.
Artificial selection
The process of breeding plants and animals with desirable characteristics in the hope that their offspring will inherit them.
Characteristics
An attribute of an individual. E.g. tall plant, brown hair
Continuous variation
Variation that shows a range. E.g. height and weight
Diploid
Cell with the full complement of chromosomes (46 in humans)
Discontinuous variation
Variation that is either/or. E.g. Blood groups
Founder effect
The loss of genetic variation that occurs when a new population is established by a very small number of individuals from a larger population
Gene pool
Refers to the total number of genes of every individual in a population
Genetic diversity
The total number of genetic characteristics in the genetic make-up of a species
Gene flow
The movement of genetic material from one population to another
Heredity
The process by which characteristics are given from a parent to their child through the genes
Natural selection (differential survival rates)
Organisms with characteristics best suited to their environment become more successful, and so expand in numbers
Population bottleneck
An event that drastically reduces the size of population, may be caused by various events such as an environmental disaster
Pure breeding
A group of identical individuals that always produces offspring of the same phenotype when interbred; are homozygous individuals
Random fertilisation
Random fusion of a male gamete with a female gamete during sexual reproduction
Variation
The differences among parents are their offspring or among individuals in a population
What is Sickle Cell disease?
A group of disorders that cause red blood cells to become misshapen and break down.
What does sickle cell do to the body?
As they do not move easily, the red blood cells can block blood flow. The blocked blood flow through the body can lead to serious problems, including stroke, eye problems, infections, and episodes of pain called pain crises.
How does Sickle Cell affect red blood cells?
Some red blood cells are shaped like sickles or crescent moons. These sickle cells also become rigid and sticky, which can slow or block blood flow.
What is anemia?
Sickle cells break apart easily and die. Without enough red blood cells, the body can’t get enough oxygen. This causes fatigue.
What are specific symptoms of sickle cell?
-Anemia
-Episodes of pain
-Swelling of hands and feet
-Frequent infections
-Delayed growth or puberty
-Vision problems
What causes sickle cell?
Caused by a change in the gene that tells the body to make hemoglobin. Hemoglobin is the iron-rich compound in red blood cells that allows these cells to carry oxygen from the lungs to the rest of the body. The hemoglobin associated with sickle cell anemia causes red blood cells to become rigid, sticky and misshapen.
What is hemoglobin?
Hemoglobin is the iron-rich compound in red blood cells that allows these cells to carry oxygen from the lungs to the rest of the body
What happens if both parents are carriers of sickle cell?
For a child to have sickle cell anemia, both parents must carry one copy of the sickle cell gene and pass both copies to the child.
What happens if only one parent is a carrier of sickle cell?
That child will have the sickle cell trait. With one typical hemoglobin gene and one sickle cell gene, people with the sickle cell trait make both typical hemoglobin and sickle cell hemoglobin.
Their blood might contain some sickle cells, but they generally don’t have symptoms. They’re carriers of the disease. That means they can pass the gene to their children.
Who does sickle cell most commonly affect?
In the United States, sickle cell anemia most commonly affects people of African, Mediterranean and Middle Eastern descent.
